Probably the best RGB software that there is. Works with almost every products from every major brand and also lets you sync everything, without the need for different branded bloatware.
Rainmeter is mostly used to costumise your Windows experience however you want with very diverse addons available. Droptop 4 is the star of the show here. It's a simple top bar, as you'd see on Mac or Linux, but for Windows! It's costumisable through a GUI, or through a config file if you're comfortable with that.